Method of forming bearings



l April 8,1s3o.A

L. '.l. sAuER El' AL uETHoD oF romane BEARINGS Filed Oct. 22., 1926 v n l l l l l l l l l I l l I l n n l l 2 Sheets-Sheet. 1

April s, 1930. l.. J. SAUER er m. 1,753,337

METHOD 0F FORMLNG BEARINGS med oct. 22, 192e 2 sheets-sheet 2 -30 ning of the third or final Patented Apr. 8, 1930 LOUIS J. SA'UER, OF OAK PARK, AN D CHARLES H.

JOY, JR., F CHICAGO, ILLINOIS,

' ASSIGNORS TO CHARLES H. JOY, SR., 0F CHICAGO, ILLINOIS METHOD OF FORMING BEARINGS Application led October 22, 1926. Serial No. 143,490.

This inventidn relates to a new and improved method of forming a bearing.

One of thefobjects of our invention is to provide a new method for forming a bearing which will lessen the cost of production.

Another objectof our invention is to provide anew method for forming a bearing which will reduce the waste and the number of operations to a minimum.

Another object is to provide a new metho which will improve the product.

A further object is to provide an improved method of forming a bearing member from flat stock by a cold working process. Y

Further objects will appear from the description and claims. In the drawings in wlich our invention is illustrated:

1 ing t e blank and the special tool and die for performing the first step in the operation.;

Fig. 2 is a similar view showing the beginning of the 'succeeding or second step in the operation; Y l

Fig; 2A is a showing of an arcuate gradient as contrasted with a gradient of different inclinations acting successively;

Fig. 3 is a similar view showing the completion of the second step;

Fig. 4 is a similar view showing the beginste Fig. 5 is a vertical sectional i/)iew of theresultant bearing; .and

Fig. 6 is a vertical sectional view of the t slidin punch. y

Re erring to the drawings, the following is a description of our cold work process for turning fiat discs of'a high carbon chrome steel into annular rings for ball bearings. First, the blank 10 is Apunched-from a steel strip stock of a de'nite thickness and a hole .pierced in the center thereof. The outside diameter, the diameter of the hole, and the thickness of the metal are all co-relative, andL the-finished annular ring is definitely proper-- tional to the original dimensions of the blank, although these proportions vary somewhat 'for each different size of annular ring.

This blank or iat'disc hole, thickness, fully and properly proportioned one. to the 10, with its inside 'is at about the end of the re l is a vertical sectional view showers, the workin the and outside diameter careother, placed in the nest 11 of the die 12.

where the punch pushes through the hole and the shoulder of the punch engages the folded edge of the disc,

the tapers are made to give a compression support to keep the smaller diameter of the drawn piece from breaking.4 This position stroke, as shown in dotted lines, and the turned disc is pushed from hereinto a container or basket by the piece following. The die throat has several tapers of different inclinations whichact progressively,-and at no time stop the movef ment of the ring past their faces, while each taper with its predetermined angle is essential in successfully turning the blank.

These' tapers of different inclinations will hereinafter be referred to as progressive tapers. As the piece passes overthese tappiece is graduallyincreased, that is, with each succeeding taper, a greater strain is set up in the piece. However, the work or strain in the piece is the greatest upon its initial movement into a new' angle of inclination whereafter the work or strain is relieved in its further movement along the face of this inclination.

The aforementioned relief is clearly illustrated by the showing in Fig. 2A, wherein several different inclinations which act successively are contrasted with an arcuate inclination. vIt will be lapparent that were the work gradually increased in the piece with no relief, an arcuate gradient would result; whereas, if the work were gradually increased in the piece with an 'allowance for relief at stated' intervals, a gradient composed of suc- 'cessive tapers of different inclinations would result.

As the result of these progressive tapers, r the pieceis deformed to the limit of its elasticity, as at A, where the action of the stress is at its maximum, whereafter the action of the stress is reduced and the strain in the piece is relieved by means of the tapered face portion until the point'B is reached, where the action of the stress is again greater and the piece is further deformed to the limit of its elasticity and the aforementioned action is repeated.

Referring to Fig. 2A, it will be seen that the die at the various points A, B, and C, provides in effect a series of annular fulcrums at these points about which the ring is bent or turned by the action of the punch 13. The blank 10 first tilts or turns about the annular fulcrum through the point A under the action of the punch 13 until the lower outer face of the blank comes into contact with the die at the point B: thereafter, the blank (which is now in the form of a conical collar) tilts or turns about the annular fulcrum through the point B until the outer surface of the blank or collar comes into contact with the die at the point C: thereafter, the blank is bent or turned about the annular fulcrum through the point (l. During this operation the sides of the conical blank or collar increase in steepness progressively.

Before the next operation, the rings are annealed so the strains of the first operation shall be removed; in fact, an annealing operation is necessary between each action.

In this second operation the piece is inverted, so the taper end 16 with the smaller diameter engages the punch and the larger diameter 17 rests in the die nest 118. The throat of this also contains a series of progressive tapers which compress and iron the metal in much the same manner as the first operation. but of course the tapers have different angles` the work on the metal is much more severe because an ironing action is introduced in this operation. Here the metal is made to flow upward against the direction of the punch down travel and the reaction force working in the opposite direction, grips the side of the punch with such great pressure that in order to avert rupture it must be relieved by a sliding punch 18, which, independentof the punch shoulder, moves with and yields to the force. This gripping force acts on the punch side asthe shoulder 19 of the punch is forcing the ring through the die, and it pulls downward on the side with lgreater velocity than the movement of the shoulder of the punch through the downward part of the cycle. e.

The ring in this operation is reduced in outside diameter and thickness, and increased in height. It is ironed to its new form by means of two factors; first, the punch which sizes the inside diameter, and second, the

tapers in the throat of the die which sizesrthe,

outside diameter. The ring is now submitted to the important annealing operation, heretofore referred to. A

After the shoulder 19 of the punch pushes the ring ahead of it, it will be seen that the lower or front edge of the collar or ring actually moves faster than the shoulder 19 itself because of the fact that the distance between the adjacent surface of the die and punch is less than the average thickness of the metal in the ring or collar so that the material in the collar is contracted and squeezed and forced to flow faster than the shoulder which is forcing it downwardly.

In the third operation` the ring is worked to its exact machining dimensions for a ball bearing race. A sliding punch and a die with the correct set of progressive tapers iron the metal to a uniform thickness throughout its length, square the corners, and size to a predetermined limit the inside diameter, the outside diameter, and the height.

This alternate cold working and annealing treatment breaks up the lanular condition of the perlite and forms an envelope about the carbide found in commonly annealed stock. This structure is desirable because in the attendant annealing treatment there is an incomplete absorption of the spheroidal carbide and the result is a condition of structure analogous to that in bearing metals, such as babbitt and the like. In this method the martensite or body of steel is stiffened and supported by the carbide remaining undissolved, the latter being very hard and capable of withstanding eXtreme wear. The reduction or ironing of the metal within limits andA the use of a predetermined pressure in the ironing operations are important features.

Tests show that the 'hardness of the material is greatly increased by this method and that no internal strains are set up as in other methods.

The successive alternate ironing and annealing breaks down the internal strains due to the prior treatment of the metal at the mill.

The sliding punch 18 comprises a body portion 20 of a usual type having a central core portion 21 which is yieldably supported in said body portion and extends downwardly therefrom. The core portion 21 preferably consists of a. one-piece casting of two different diameters whereby a' shoulder 22 is formed. The smaller diameter of the core portion is supported in a central aperture 23 in the main body portion while the larger diameter of the core portion is countersunk in a second central aperture 24 in the main body portion. One end of a spring 25 is fastened to a screw member 26, which latter is mounted in an insert 27 at the upper end of the body portion 2() and is stationary therewith, while the,v other end of said spring 25 is secured to the' movable core portion 21. This spring normally acts to hold the shoulder 22 of the core portion 21 against its seat.

The core portion 21 also contains an elon-I gated aperturevtherethrough and horizontalin order to avert rupture,

ly thereof through which a pin 28 extends to be secured at its outer ends to the main body portion 20. This pin is for the purpose of limiting the movement of the core portion relative to the main body portion. The ac'- tion of this sliding punch has been hereinbefore referred to. In the ironing action, the metal is made to flow upwardly against the direction of the downward movement of the punch and the reaction for'ceworking in the opposite direction grips the side of the core portion 21 with such great pressure that said core portion moves withand yields tovthis force against the action of the spring 25 and thereby moves this core portion downwardly with greater velocity than the movement of the shoulder 19 of the punch.

This application is a continuance as to common disclosure of our prior aplications Serial Numbers 688,693, filed January 26, 1924, and 67,708, filed November 9, 1925.

We claim:

1. A method of forming an annular bearing member comprising forming a collar from sheet metal, inserting a cylindrical forming member into said collar in such manner that its axial movement is controlled by its engagement with said collar and forcing said collar and cylindrical forming member through a die, and during this operation exerting pressure on the edge of the collar to force it through the die, the distance between the adjacent surfaces of the die and cylindrical forming member being less than the average thickness of the metal in the co1- lar before the operation, vwhereby the distance between the edges of the collar is increased as the collar is pushed through the die.

2. A method of forming an annular bearing member comprising forming a collar from sheet metal, inserting a cylindrical forming member into said collar in such manner that its axial movement is controlled by its engagement with said collar and forcing said collar and cylindrical forming member through a die, and during this operation exerting pressure on the edge of the collar to force it through the die, the distance between the adjacent surfaces of the die and cylindrical forming member being less than the average thickness of the metal in the collar before the operation, of the collar advances faster than the edge on which pressure is being exerted.

3. A method of making an annular bearing member comprising making a flat sheet metal ring, supportinor the outer edge of said ring on an annular fiilcrum, exerting pressure on the inner part of said cold to bend it -about said fulcrum into a substantially conicalcollar, annealing said collar, inserting a cylindrical forming member into said collar in such manner that its axial movement is controlled by its engagement ring while with said collar, and forcing said collar and cylindrical forming member through a die, and during this operation exerting pressure on the edge of the collar, the distance between adjacent surfaces of the die and cylindrical forming member being less than the average thickness of the metal in the collar before the operation whereby the front edge of the collar advances faster than the edge on which pressure is exerted.

In witness whereof we have hereunto subscribed our names.

LOUISl J. SAUER.

CHARLES H. JOY, JR.

whereby the front edge 

